Tunneling-machine.



G. A. FOWLER. TUNNBLING MACHINE. APPLICATION FILED MAY 22, 1909.

Patented July 4, 1911.

6 SHEETS-SHEET l.

COLUMBIA PLANOGRAPH Cm. WASHINGTON, D. c.

G. A. FOWLER, TUNNELING MACHINE. APPLICATION FILED MAY 22, 1909.

Patented July 4, 1911.

6 SHEETS-SHEET 2.

col-Ilium PLANOORAPH 1:13., WASHINGTON, D. c.

" G. A. FOWLER.

TUNNELING MACHINE.

APPLICATION FILED MAY 22, 1909.

Patented July 4,1911.

6 BHEBTBSHEET 3.

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COLUMBIA PLANOORAPH CCL. WASHING-r0! D c G. A FOWLER. TUNNELING MACHINE.

APPLIUATION FILED MAY 22, 1909.

Patented July 4, 1911.

6 GREEN-SHEET 4.

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TUNNBLING MACHINE.

APPLIOATION IILB D MAY 22, 1909.

Patented July 4, 1911.

6 SHEETS-SHEET 6.

COLUMBIA PLANOORAPH c0., WASHINGTON. D. c.

G. A. FOWLER.

TUNNBLING MACHINE.

APPLICATION rum) MAY 2a. 1909.

996,842, Patented July 4, 1911.

6 BHEETE-SHBET 6- orrro TUNNELING-IVIACHINE.

To all whom it may concern;

. Be it known that'I, GEORGE A. FOWLER, a citizen of the United Statesof America, residing at the city and county of Denver and State ofColorado, have invented a new and useful Tunneling-Machine, of which thefollowing is a specification.

My invention relates to improvements in tunneling machines.

The object of the invention is to provide a suitable frame mounted uponwheels, said frame being provided at its forward end with a drill headprovided with a plurality of fluid operated drills, said head beingpivotally mounted on the frame and adapted to swing from side to side inthe arc of a circle, upon a vertical axis, means being provided foradmitting fluid under pressure to said drills, and for automaticallyswinging said head from side to side and for manually moving saidmachine forward against the breast of a tunnel.

A further object of the invention is to provide in connection with amachine of this character, a mucker, which is in position to receive therock cuttings and which is adapt ed to receive air under pressurewhereby the rock cuttings are blown rearward and are deposited upon anendless conveyer supported upon the frame, means being provided foroperating said conveyer and for automatically swinging said head fromright to left, said automatically operating means being adapted toreverse the movement of the head at a predetermined point in its travel.

A further object of the invention is to provide a wheeled frame having acutter head pivoted upon o-ne end, means for swinging said head fromside to side and for automatically reversing its movement at a predetermined point in its travel, said head being provided with aplurality of fluid operated drills which are adapted to form either asquare or an arched tunnel, means being provided for raising or loweringthe rear end of said frame.

A still further object of the invention is to provide in connection witha suitable supporting frame, a cutter head which is pivotally mounted onsaid frame to swing from side to side, said head being provided with aplurality of rows of fluid operated drills which radiate from a commonpoint, the drills in one row being arranged to alternate with those inthe adjoining row or rows, means being provided for moving the ma-Specification of Letters Patent.

Application filed May 22, 1909.

' Patented July 4, 1911.

Serial No. 497,775.

chine forward as the breast of the tunnel is cut away.

These objects are accomplished by the mechanism illustrated in theaccompanying drawings, in which:

Figure 1, is a side elevation of the improved tunneling machine, theinclosing plates on the near side of the machine being removed. Fig. 2,is a plan view of the same. Fig. 3, is a rear end elevation of themachine, one pair only of the side bearing rollers being illustrated.Fig. 4, is a front end elevation of the same, the cutter head beingremoved, and the worm gear by which said head is operated and also itsbearing block being shown in section. Fig. 5, is a side elevation partlyin section of the cutter head, the drill cylinders and drills beingremoved. Fig. 6, is a side elevation of a portion of one of the halfsections constituting the cutter head, looking at its inner face. Fig.7, is a horizontal sectional view on the line 77 of Fig. 5. Fig. 8, is asimilar view on the line 88 of Fig. 5. Fig. 9, is a sectional viewthrough a portion of the cutter head on the line 9-9 of Fig. 5. Fig. 10,is a front elevation of a portion of the cutter head, showing thearrangement of the sockets which receive the drill cylinders. Fig. 11,is a front elevation partly in section of the cutter head reversingmechanism. Fig. 12, is a horizontal sectional view of the engine used inconnection with said reversing mechanism. Fig. 13, is a transversevertical section of said engine. Fig. 14, is a front elevation of thesupporting means for the worm pinion, by which it meshes with a wormgear on the rear axle of the machine for propelling the machine forward.Fig. 15, is a detail plan view illustrating the means of holding saidpinion in engagement with said gear. Fig. 16, is a sectional view on theline 1616 of Fig. 15. Figs. 17 and 18 are plan views respectively of theupper and lower supporting plates for the worm pinion shown in Fig. 14;.Fig. 19 is a vertical longitudinal sectional view through the muck receiver. Fig. 20, is a plan view thereof. Fig. 21, is an enlargedsectional view of the drill head showing a drilling engine ar ranged inoperative position. Fig. 22, is an end view of the sleeve, showing thestationary valve in position to admit air to the rear of the hammerpiston. Fig. 23, is a sectional view on the line 23*28 of Fig. 21,showing the valve in position to admit air at the forward end of thepiston. Fig. 24, is a perspective view of the valve plate or stationaryvalve. Fig. 25, is a perspective View of the rotatable valve. Fig. 26,is a side view partly in section, of the striking pin, the rear end ofthe drill being shown in locked position therewith. Fig. 27, is asectional view on the line 2727 of Fig. 26. Fig. 28, is a side elevationof a form of drill head which is adapted to cut an arched tunnel, andalso a muck channel in the floor of the tunnel. Fig. 29, is a sectionalview showing the form of tunnel cut by the drill head shown in Fig. 28.Fig. 30, is a view of one of the clutch reversing levers. Fig. 31, is asectional view through the piston hammer sleeve, the piston hammer beingpartly broken away, to show the feather key by which it is preventedfrom axial rotation within said sleeve. And Fig. 32, is a frontelevation of the hammer piston.

Similar letters of reference refer to similar parts throughout theseveral views.

Referring to the drawings, the numeral 1, designates the supportingframe of my machine. This frame is preferably constructed of channelbars or beams, but may be made of other material if desired, andcomprises four longitudinal base beams 2 and 3, which are preferablyarranged in pairs side by side on opposite sides of the machine, the twobeams of each pair being arranged at sufficient distance apart toreceive the rear supporting wheels 4, between, them, upon which the rearend of the frame of the machine is mounted. To the base beams aresecured corner standards 5, and central standards 6, to which aresecured longitudinal roof beams 7, which are connected at their oppositeends by Z bars 8. A central longitudinal channel beam 9 is supportedupon and secured at each end to the Z bars, and transversely arrangedchannel plates 10 are secured at their ends to the beams 7 and 9, nearthe front end of the frame. Each pair of beams 2 and 3 are connected byplates 11, and the beams 2 and 3 of each pair are connected by plates12. The front end of the frame is mounted on a pair of small rollers 13,and these rollers are placed between the beams 2 and 3, and are eachmounted on an axle 14, which axles are journaled in boxes 15, secured tothe under sides of the beams.

The rear wheels 4, are preferably larger than the rollers 13 that carrythe front end of the frame, and are mounted on an axle 16, which extendsacross the frame and is journaled in eccentric sleeves 17 which arerotatably mounted in boxes 18, which are bolted to the upper edge of thebeams 2 and 3, on each side of the frame. These eccentric sleeves areeach secured to the terminal ends of yoke-shaped hand levers 19, theyoke portion of which straddles the wheels. Segment plates 20 aresecured to the frame, and partially surround each wheel, and the platesare provided wit-h a plurality of holes 21, which are adapted to receiveremovable pins 22, which are each passed through apertures in the levers19, and in any one of the holes 21 of the adjacent segment plate 20. Bythis arrangement, the yoke levers can be moved to turn the eccentrics intheir boxes to raise or lower the axle and wheels, either in unison orindependently, and by inserting the pins 22, in the holes in the tops ofthe yoke levers, and in registering holes in the segment plates, theeccentric sleeves may be secured at the desired adjustment. Theeccentrics are positioned in the boxes to stand with their throwportions in horizontal planes, and with their operating lever 19 lockedto the segments in a vertical position, in which position the framestands in a horizontal plane, but when the eccentrics are turned, therear end of the frame is either raised or lowered according to thedirect-ion of movement of the levers 19.

The object of raising or lowering the rear end of the frame above orbelow a horizontal plane, is to enable the machine to form a tunnel ofany practical upward or downward grade or pitch of inclination to ahorizontal grade, and also for the purpose of guiding the machine backto the specified grade of the tunnel when the machine accidentally worksaway from it, as it is apt to do when streaks of soft shattered rock ortalcky ground are encountered.

The frame is moved forward or backward on the floor portion of a tunnel,by a worm gear 23, which is mounted on and secured to "the axle 16, andis operated by a worm pinion 24. The worm pinion 24 is positioned in avertical plane in mesh with the worm gear, and it is provided with ashaft 25, which extends beyond its opposite ends and is journaled atopposite ends of the pinion in bearing plates 26, which are bolted to apair of parallel yokes 27, which extend around the axle 16, and hold thepinion in mesh with the gear, as shown in Fig. 16. The pinion and itsshaft are further supported by upper and lower bracket plates 28 and 29,respectively, which are bolted to the inner base beams 3, as shown inFig. 14. These brackets are provided with open ended bearing recesses30, through which the shaft 25 passes, and in which it is permitted aslight rocking movement to allow the worm pinion to remain in mesh withthe worm gear when the said frame is raised or lowered by the turning ofthe eccentric sleeves 17. The shaft 25 of the worm pinion extends abovethe hanger, and at its upper end an operating arm or lever 31 ispivotally secured to turn freely on the end of the shaft. This arm isprovided with a pawl 32, which is arranged to be held by a spring 33, inengagement with notches in a disk 34, which is keyed to the top endportion of the shaft. This pawl is connected by a rod 35, to a handlever 36, which is pivotally attached to the handle end of the arm 31.This auxiliary handle is arranged relative to the main handle to begrasped by the hand of the operator, with the main handle, to withdrawthe pawl from the notches in the disk 34. The pinion is manually rotatedto turn the worm gear by oscillating the arm 31 back and forth, and indoing this the two handles are grasped to disengage the pawl from thedisk 34, and the lever is moved in one direction and the auxiliaryhandle released to allow the spring to throw the pawl into a notch,after which the arm is moved in the opposite direction, and the shaftand pinion are thereby rotated.

To the sides of the base and roof beams of the frame are pivotallysecured lateral bracing arms 37. These four arms are hinged at theirinner ends to plates 38, which are secured by bolts or rivets to thecentral portions of said beams. The arms 37 are in the form of channelbars, and to their outer ends are riveted hinge straps 39, which arebifurcated at their free ends to receive the bifurcated ends of bolts40, and in the bifurcated ends of the bolts are supported rollers 41,which are pivotally mounted upon pins which pass through them, andthrough the bifurcated ends of the bolts 40, and hinge straps 39. Thebolts pass through nuts 42, having convex faces, which rest incorresponding concave faces of plates 43, which are bolted to the beams,and which are provided with holes through which the said bolts pass. Byadjusting the nuts upon the bolts, the outer ends of the arms 37 aremoved out from the frame against the opposite sides of the tunnel, andthe rollers 41 are adapted to bear and roll against the side walls ofthe tunnel, as the frame is advanced against the breast thereof by theworm pinion and its gear. Upon the central portion of the frame 1, Iplace a suitable motor 44, preferably an air operated single cylinderslide valve engine, which is placed in a vertical position, with itscylinder 45 close to the base beams of the frame, and with itsconnecting rod 46 extending vertically upward toward the roof of theframe. The engine is supported in this position by suitable braces 47,which are secured to the engine at one end and to a base plate 48, whichis secured to the base beams of the frame. To the upper cylinder head isintegrally connected a distance piece 47, having a platform 47 at itsupper end, to which are bolted bearings 47", in which the driving shaftof the engine is mounted.

A pipe 49 is connected to the valve chest of the engine, and extends toand is connected to an air receiving tank 50, which is placed on thefloor of the frame adjacent to the engine, and the engine is providedwith the usual exhaust port. A supply pipe 51 extends from this tank tothe rear end of the frame, and is adapted to be connected with a supplyof compressed air.

The engines driving shaft 52, is provided with a fly wheel 52 on oneside, and with a belt pulley 53 on its opposite side. A shaft 53 extendslongitudinally through the frame, and centrally of its width, and isjournaled in hangers 54, which are bolted to the under side of thechannel beam 9. This shaft carries a pulley 55, which is secured to it,and is driven by a belt 56 from the driving pulley 53 of the engine.This shaft extends to the front end portion of the frame, and a bevelgear 58 is secured to its end. This bevel gear meshes with two bevelgears 59 and 60, which are secured on the ends of two shafts 61 and 62respec tively, which are journaled at right angles to the main shaft53*, in a three-bearing hanger 63, which is also secured to the channelbeam 9. The bearings for the shafts 61 and 62 are in line, and the thirdbearing is at right angles to these hearings and sup ports the forwardend of the shaft 53*. These shafts 61 and 62 extend in oppositedirections from the horizontal center of the main shaft and from eachother, and are rotated in opposite directions by the gear 58 and thegears 59 and 60. On each of the shafts 61 and 62, sprocket wheels 64 and65 respectively are secured, on which sprocket chains 66 and 67respectively are mounted. The sprocket chains extend to and are mountedon sprocket wheels 68 and 69 Fig. 11, which are slidably mounted onsleeves 70 and 71, which are slidably and rotatably mounted on a shaft72, that is journaled in bearing blocks 73, that are secured to thebeams 2 and 3 of the frame.

The two gears 59 and 60, and their shafts, are driven by the gear 58 onthe end of the shaft 53*, in opposite directions, and this oppositedirection of rotation is imparted to the sprocket wheels 68 and 69 onthe sleeves 70 and 71, by the sprocket wheels and the sprocket chains. Aworm pinion 74 is formed or secured on the central portion of the shaft72, which pinion meshes with and drives a semi-circular worm gear 75,the hub of which is pivotally mounted on a pin 76, that extends throughoverlapping lugs 77, formed on a two-part drilling head 78, and whichalso extends through a block 79 that is supported in a yoke-shapedchannel beam 80, the ends of which are bolted to the inner base beams 3.

The sprocket wheels 68 and 69 are secured to the sleeves 70 and 71, byfeather keys 81, which permit a sliding movement of the sleeves withinthe said sprocket wheels, but lock the said wheels to the sleeves, sothat the sleeves are rotated by the wheels. The wheels 68 and 69 areheld against lateral sliding movement by brackets 82, having upwardprojections 83, between which the said wheels lie, and the projectionsprevent the wheels from sliding with the sleeves, when the said sleevesare moved, as will be presently more fully explained.

The drilling head 78 is provided at its upper end with apertured lugs84, a lug being formed on each half section of the head, and arranged tooverlap, so that their apertures will register. A yoke-shaped bracket 85is secured to a bar 86, which is secured to the upper portion of theforward uprights 5, of the frame, and the bar 86 is further supported bybraces 87, which are secured to the forward Z bar 8. The bracket 85 issupported from beneath by braces 88, which are secured to the bracket,and to the uprights 5. Within the bracket 85, is secured a block 89,having an aperture in axial line with the aperture in the block 79, anda pin 90 is passed through the apertured lugs 84 and the block 89. Thusthe pins 76 and'90 support the drill head, and permit it to be swungfrom right to left in the arc of a circle.

The worm pinion 74 and the worm gear 75 are adapted to swing oroscillate the drill head in a horizontal plane, and in a. semicircularpath from one side of the tunnel to its opposite side, through themedium of the engine and shafting, and the bevel gears 58,

59 and 60, the sprocket wheels 64 and 65, the sprocket chains 66 and 67,and the sprocket wheels 68 and 69. The sleeves 70 and 71 are formed withclutch teeth 91 on their inner ends, which are adapted to engage similarteeth 92 on the opposite ends of the pinion 74, and these clutch teethmay ,be of any suitable form. The sleeves, which are rotated in oppositedirections, are operated to alternately engage the clutch faces of thepinion 74, thereby to reverse the clirection of the rotary movement ofthe said worm pinion at the ends of the reciprocal swinging movements ofthe drilling head from one side of the tunnel to the other, and theyalso are adapted to permit the operator to stop the head at any desiredpoint and reverse its movement as often as desired in either direction.It is essential, however, that some reliable and powerful method ofmoving these oppositely rotating clutch sleeves be employed in orderthat they may be moved in successive and regular order withoutinterfering with each other. I preferably carry out this feature of myinvention in the following mannerzTo the bearingblock 73, are secured apair of parallel angle bars 93, which are bent in the form shown in Fig.11, and which together form a bridge or support, upon the upper centralportion of which a suitable engine 94 is secured. A space is leftbetween these bars and to their under sides are bolted brackets 95, thebrackets on one bar being in line with those on the other bar. Thesebrackets are apertured and a pin 96 is passed through the apertures ofeach pair of alined brackets, and upon the pins are mounted levers 97and 97, which are yoke-shaped at each end. The lower yoke ends of eachlever. are pr0- vided at their extremities with inwardly extending lugs98, which are adapted to extend into annular grooves 99, of the sleevesand 71, which grooves may be formed directly in the sleeves, or they maybe formed by securing collars 100 upon the sleeves, as shown in Fig. 11,a space being left between each pair of collars, which constitutes thegroove.

The levers 97 and 97 are provided with elongated apertures 101, at theirupper ends, through which pass pins 102, which also pass throughenlargements on a pair of piston rods 103, and 103 respectively, whichextend out through the heads of the engine 94, and are supported instandards 94 secured to the bars 93.

The piston rods are attached to and extend from piston heads 104 and105, which are reciprocally mounted in the engine cylind-er. The enginecylinder is provided with two cylindrical bores 106 and 107, in whichthe piston heads 104 and 105 are reciprocally mounted, and thesecylinder bores are arranged in direct horizontal alinement, and areseparated from each other by a partition 108. The axial center of thispartition is provided with an aperture, in which a pin 109 is slidablymounted. This pin is made enough longer than the thickness .of thepartition to permit it to be moved by the piston heads in alternateorder far enough to move-the opposite piston a suflicient distance touncover its actuating fluid inlet port, as will be hereinafterdescribed.

The cylinder is provided with a valve chest 110, which is provided witha valve seat, and a flat slide valve 111 is seated on the valve seatwithin the valve chest. This valve is operated by a rod 112, which issecured at one end to an apertured lug 113, on the valve, and whichextends out through a stufiing box 114, on the end of the chest, and ispivotally secured at its opposite end to a lever 115, which is pivotallyconnected at its lower end to a bracket 116, secured to the bars 93. Thelower end of this lever is yoke-shaped, to straddle the adjacent pistonrod 103, and its upper end is pivotally attached to a lever 117, havinga handle portion at one end, while its opposite end is pivotally securedto a lever, comprising an upright arm 118, which is connected to thelever 117 a horizontal member 119, which is mounted in bearings 120 onthe top of the valve chest, and an arm 121, which projects at rightangles from the forward end of the member 119. The arm 121 is pivotallyconnected at its extremity to a vertical bar 122, which is slidablysupported in a guide block 123, which is secured upon the outer bar 93.The lower end of the bar 122, carries a roller 124, which is adapted tobe engaged alternately by cam plates 125 and 126, which are secured atopposite extremitiesof the worm gear 75. The cam 126 is adapted to passunder the said roller and lift the bar 122, when the gear 75 reaches thelimit of its movement in one direction, while the cam 125 passes overthe roller and thereby draws the bar down again, when the gear reachesthe limit of its movement in the opposite direction, the object of whichis to reverse the slide valve 111, as will presently be more fullydescribed.

The valve 111 is enough shorter than the length of the inside of thevalve chest to control by its alternate strokes two ports 127 and 128,which are formed at opposite ends of the valve chest, through the valveseat of the cylinder, to admit the actuating fluid from the valve chestinto the outer ends of the two piston bores of the cylinder. Anactuating fluid inlet pipe 129, in which a valve 130 is placed, isthreaded to the valve chest and extends to a pipe 131, which connectsthe air receiving tank 50 with the drill head, and an exhaust port 132in the wall of the engine cylinder connects with an exhaust chamber 133formed in the bottom of the valve, and with the atmosphere. This exhaustchamber of the valve communicates alternately with the ports 127 and 128of the valve chest, at the ends of its opposite reciprocal movements.The two piston bores of the cylinder are connected on opposite sides oftheir dividing partition 108, by a port 134, which extends from eachbore through the wall of the cylinder and below the said partition.

The entrances of this port 134 in each cylinder, are positioned at asufficient distance from the opposite sides of the partition to enablethe piston heads 104 and 105 to stand wholly between the entrances tothe port and the partition when the piston heads are against or almostagainst the partition, and the object of this port is to allow theactuating fluid topass from one cylinder to the other, and move thepistons on their outward strokes, as will be presently explained, and inorder to accomplish this, the peripheral edge port-ion of each piston isbeveled on both sides to allow the actuating fluid to flow readilybehind them when at the opposite ends of their strokes, or when onepiston is moved away from the partition beyond the adjacent portentrance, by

the impact of the other piston on the pm 109; This rotary motionreversing mechanism operates to reverse the direction of the rotarymovement of the pinion and gear I and of the drilling head in thefollowing manner: The valve 130 being opened, compressed air is conveyedthrough the air inlet pipe 129 to the valve chest. The operator thengrasps the hand operating end of the valve lever 117, and moves thevalve to one end of the valve chest, and assuming that the valve hasbeen moved to uncover the port 127, the compressed air enters thecylinder 106 and moves the piston 104 against the partition, and as itmoves to the rear end of its cylinder, its rod 103 moves the clutchoperating lever 97 with it, and this lever moves the clutch sleeve onthe driving shaft 72, away from the clutch of the adjacent end of theworm 74, and consequently uncouples it from the worm, and when thepiston 104 reaches the limit of its stroke, it strikes the pin 109 andmoves it through the partition 108, and the pin moves the piston 105away from the partition far enough to open the farther end of the port134 and allow the compressed air to flow through this port from thecylinder 106 and into the cylinder 107, and be hind the piston 105,which has been moved away from the partition by the pin far enough touncover this port to admit air behind it. The air then moves the piston105 to the front of its cylinder 107, and in doing so its piston rod 103moves the clutch sleeve 71, into engagement with the adjacent end of theworm pinion 74, and as the sprocket wheel 69 carried by this sleeve isrotating in an opposite direction from the sprocket. wheel 68 carried bythe sleeve 70, the direction of rotation that was imparted to the wormpinion before the clutch sleeve 70 was uncoupled from it, is reversed,and the drill head is swung in the opposite direction.

The operator can allow the motion of the worm to continue until thedrilling head has swung around at or close to right angles to thelongitudinal axis of the frame and tunnel, when he can at any timereverse it, by grasping the valve operating lever 117 and moving it toclose the port 127 and open the port 128. When the lever 117 is pushedto uncover the port 127, the bar 122 carrying the roller 124, is raisedby the upward movement of the arm 121, and as the worm gear 75-which isturning fromleft to right, as one looks toward the front end of themachine-approaches the limit of its movement in this direction, the camplate 125 passes over the roller 124, and draws the bar 122 down, whichmovement is imparted to arms 118, 117 and 115, thereby reversing theposition of the valve 111, and uncovering the port 128. The air thenflows behind the piston 105, and moves it to the rear of its cylinder,where it engages the pin 109, and moves it to move the piston 104 beyondthe entrance of the port 134, and when the piston 105 reaches thepartition, and uncovers the adjacent end of the port 134, the air flowsthrough the said port behind the piston 104 and moves it to the frontend of its cylinder, and in doing so its piston rod moves the clutchlever 97 to throw the clutch sleeve again in mesh with the adjacentclutch of the worm pinion 74, again reversing the direction of movementof the pinion and of the driven gear.

The drill head comprises two segmental sections 135, which are boltedtogether by a plurality of bolts 136, and the sections are each formedwith registering key seats 137, in which keys 138 Fig. 21 are placed,when the parts are assembled, and these keys prevent twisting of thesections one upon the other, and the constant strain upon the connectingbolts. Each section is provided with the rearwardly projecting aperturedhinge lugs 84, previously referred to, and these lugs are formed tooverlap so that their apertures 84 will register, and the pins 76 and 90are passed through these lugs and through the blocks 79 and 89, thushinging the drill head to the front end of the frame, so that it may beswung from side to side in the arc of a circle, as previously described.

Each section is provided with a row of cylindrical sockets 139, whichradiate from the point from which the arc of the cutter head isdescribed, and the sockets in one section alternate with those in theother section. The top and bottom sockets of each section are on thesame plane, and as this would make the intervening space between the twoupper sockets in one section and the two lower sockets in the othersection greater than the space between the other sockets, a half socket140 is formed in each sect-ion at the upper and lower end thereof, andbetween the last two sockets, which register when the sections areassembled, .and the drill placed in these two sockets will cut away therock which would be left by the two drills at each end, which arefarthest apart, as will be apparent. Back of each row of sockets alive-air chamber 141 is formed, and these chambers extend from one endof the section to the other, and communicate at each end of the headthrough passages 142, which are immediately behind the central sockets140. Each socket has a supply aperture 143 in its bottom, whichcommunicates with the adjacent chamber 141, and. in the .wall of eachsocket next to the inner face of the section is formed an exhaust port144, which opens into an exhaust chamber 145, which islocated betweenthe two live-air chambers 141, and which forms part of a larger exhaustchamber 146, which extends the whole length and width. of the head, andwhich is behind and parallel with the chambers 141. A threaded nipple147 extends through the rear wall of theexhaust chamber 146, and intoand through the dividing wall between this chamber, and one of thelive-air chambers 141, and this nipple is adapted to receive one end ofa hose 148, extending from the supply pipe 131 of the tank 50, wherebyair under pressure is admitted to the chambers 141, as will beunderstood by reference to Figs. 5 and 7.

The chamber 145 terminates at each end, where it is intercepted by thewalls of the two central sockets, and these sockets have their exhaustports 149 in these walls, and as the chamber 145 terminates short. ofthe two uppermost and two lowermost sockets, a small chamber 150 isformed in the half sections, between each two of said sockets, whichcommunicates with the chamber 146, and the exhaust ports from theuppermost and lowermost sockets communicate with this chamber 150, aswill appear by reference to Figs. 6 and 9..

At the lower end of the exhaust chamber 146, an exhaust port 151 isformed in the outer wall of each section, and these ports are connectedby pipes 195 with a pneumatic mucker, which will be fully describedhereinafter.

Any suitable character of rock drilling engine may be employed inconnection with the drill head, but I preferably employ a hammer pistondrilling engine, in which the blows of the drill bit striking mechanismare cushioned, so that the bits cannot be driven into soft or seamy rockor into talcky ground beyond a stroke of predetermined limit, and thefront ends of the engines cannot be broken or knocked out by the actionof the hammer piston. It is also preferable to employ removable sleeves.or cylinders which fit into the sockets 139, and in which the hammerpistons and other movable parts of the engine are mounted, and which receive the wear of these parts. These sleeves 152 are'pressed into thesockets 139, and rest against the bottoms thereof. They are shorter thanthe depth of sockets, the outer ends of which. are threaded .for asuitable distance, and apertured nuts 153 are screwed into thesockets,against the outer ends of the sleeve, to secure them in place.

Thesleeves are counterbored for a short distance at, each end, as shownat 154 and 155, and beforevthey are secured withinthe sockets, they areeach supplied with the parts which make up the drilling engine, andwhich are as follows A rotatable disk valve 156 is placed in thecounter-bore 154, so as'to rest against its shoulder. This valve has acentral aperture through which is inserted the reduced end of a rifledbar 157, which is secured to the valve by a .pin 158, which passesthrough the valve and the said reduced portion of the rifled bar. Thevalve is provided with a radial port 159, which extends entirely throughit, and with a port 160, which is in the form of a chamber extendinginto the valve from its peripheral edge, and a port 161 extends from theport 160 through the rear side of the valve. A port plate or disk 162 issuitably secured in the end of the sleeve against the valve 156, andthis plate is provided with a port 163, with which the port 161 of thevalve 156 registers, in one position of the said valve, and it is alsoprovided with a port 164 whichextends out through its peripheral edge.The port plates are of the same diameter as the apertures 143 in thebottoms of the sockets 139.

The rifled bar 157 is provided with longitudinally disposed grooves 165,preferably four in number, which extend from the valve to the end of thebar, and one side of each groove at its forward end terminates in aninwardly projecting cam surface 166, which reduces the groove to onehalf of its width at this point, while the opposite sides of the rearends of the grooves are formed wit-h similar cam surfaces 167. Therifled bar extends through a rifled nut 168, which is threaded in theend of a hollow hammer piston 169, which delivers its blows against astriking pin 170, which is positioned in the counter bore 155. Thisstriking pin consists of a head port-ion 171 and a drill holding hubportion 172. The head portion reciprocates between the shoulder of thecounterbore of the cylindrical sleeve, in which it is reciprocallyconfined, and the nut 153 which is provided with an axial aperturethrough which the hub of the striking pin projects reciprocally andextends far enough beyond the nut to receive and be locked to the shankend of a drill bit 173.

The drill bit may be removably secured to the projecting end of thestriking pin in any suitable manner, but 1 preferably carry out thisfeature of my invent-ion in the fol lowing manner: I form a recess orsocket 174 in the end of the striking pin to receive and fit the endportion of the drill bit with a free but close fit, and across theprojecting end of the outside surface of the striking pin into thisaperture I form a keyway 175. A circumferential keyway 176 is alsoformed around the end of the drill shank in a position to register withthe keyway in the hub of the striking pin, when the drill bit isinserted therein. The drill bit is then locked to the shank of thestriking pin by a spring key 177, which fits in the keyways of both thestriking pin and of the drill bit. This spring key comprises a springband 17 8, one end of which is bent to form a U-shaped cross section,and this bent end 179 constitutes the key. The ends of the spring arearranged at a distance apart that will enable them to spring over theend of the striking pin. The hammer piston is feathered to thecylindrical sleeve by a key 180, which extends through the sleeve andprojects into a keyway 181, formed between the opposite ends of thehammer piston. The key has a notch 182, which registers with a recess183 in the sleeve, in which recess a suitable implement may be insertedto withdraw the key, in order to remove the piston hammer from thesleeve. The cam surfaces of the rifle flutes of the rifle bar occupy buta short portion of the stroke of the hammer piston, and its rifled nuton the rifle bar. The cam surfaces at the front and rear ends of therifle bar have a short straight portion be yond them, and the positionof these cam surfaces may be changed either nearer the ends of the riflebar or farther away from them than I have illustrate-d, if it is desiredto secure a quicker or slower action-of the valve.

The sleeve 152 has a longitudinal groove or port 184 in its peripheralsurface, which opens at its rear end into the port 160 of the valve 156,and at its opposite end it extends through the sleeve forward of thehammer piston, and when the valve is in the position shown in Fig. 23,live air entering through the port 163 is admitted through ports 161,160, and 184, to the front of the hammer piston, and the air back ofsaid piston exhausts through the port 159, and through a port 185 in thesleeve, which registers withone of the exhaust ports 144, and when thevalve is in the position shown in Fig. 22, live air enters the rear endof the sleeve through ports 164 and 159, and the air in front of thehammer piston exhausts through ports 184, 160, 185, and 144. When therifled nut 168 contacts with the cams 166 of the rifled bar on theforward stroke of the hammer piston, the valve 156 is turned to theposition shown in Fig. 28, and when the said nut engages the cams 167 atthe rear end of the rifled bar, the valve is thrown to the positionshown in Fig. 22.

The actuating fluid is also used to cushion the striking pins and holdthem at the end of their forward position, to receive the full blows ofthe hammer pistons, and it passes to the rear of the heads of thestriking pins, through a port 186, which is grooved in the peripheralsurface of the sleeve at a point opposite the port 184. The ports 186communicate at their rear ends with the live air chambers 141. The ports186 are arranged to enter the counterbores 155, behind the striking pinat the rear of their head portions, in order to allow the striking pinwhen driven back by ablow of the hammer piston to cross this port and tocompress for an instant the air filling the space between this port andthe head nut 158, thus cushioning the striking pin so that it cannothammer against the said nut, and also preventing the striking pin fromhammering the drill bit when it is not held up against and in operativedrilling relation to the breast of the tunnel.

While the drill bits are firmly supported by the striking pins of thedrilling engines, I preferably provide an additional support for them atabout the center of their lengths, in which they are slidably mounted.This support consists of a sheet iron plate 187, which is supported at adistance of about one-half of the length of the drills by a brace 188,which is secured to the face edge of the head. This plate is providedwith apertures of the shape of the drill steel used, through which thedrill bit extends and fits loosely but close enough to support the drillbits against springing to either side of their central positions. Inorder to discharge the muck or rock drillings as fast as it is made, itis necessary that it be guided to drop directly to the floor as fast asit is drilled off of the breast of the tunnel by the drill bits, andconfined to the area of the drill bits instead of permitting it to flyin all directions from the drill bits, and form a bed all over the areaof the floor at the foot of and adjacent to the breast of the tunnel.

I preferably carry out this feature of my invention in the followingmanner: To the front of the guide plate 187, I secure at intervals arms189, on which I secure in any convenient manner curtains 190, of canvasor rubber or other suitable material. These curtains extend close to therock drilling ends of the drill bits, and consequently they extend closeto the breast of the tunnel when the drill bits are drilling against it,and the pieces of rock and fine cuttings instead of flying in alldirections from the drill bits, strike these curtains and are confinedto a space of the width of the gang of drill bits, and fall to the floorof the tunnel, where they are shoveled or otherwise moved to the rear ofthe tunneling machine.

I preferably convey the muck to the rear end of the drilling head bymeans of a pneumatically operating muck conveyer, which is secured tothe lower edge portion of the drilling head and moves with it as itswings across the breast of the tunnel, and is provided with a shovelinglip portion that moves along the floor of the tunnel against or veryclose to its surface, as the drilling head swings from one side wall tothe other, under any muck that falls outside of the side curtains, andthat is arranged to extend close to the rock drilling points of thelower drill bits of the drilling head under drill bits and close enoughto the breast of the tunnel and under all of the drill bits in such amanner that the muck falls directly onto the shoveling lip end of theconveyer. This muck conveyer consists of a pan 191, which is providedwith a muck shoveling lip 192,

at its forward end, and with a discharge spout 193 at its rear end, andan inclined floor 19 1 composed of overlapping slats or strips, spacesbeing left between the strips to admit of air under pressure beingforced therethrough, and the strips being overlapped so that the airwill be directed toward the discharge spout. This floor extends from theshoveling lip to within a slight distance of the spout, and the spacebetween it and the bottom of the pan 191 forms an air receiving chamber195, which is supplied with air from the exhaust cham her 146 of thedrill head, by pipes 195*, which connect with the opening 151 of theexhaust chamber. The shoveling lip is formed by curving up and over andback upon itself the terminal end of the bottom plate, and the top edgeof this lip extends backward from the end substantially parallel withthe bottom of the pan a short distance, and forms the end of an airpassage space along the inside of the bottom of the pan, as will be morefully described hereinafter. The edge of the lip is formed withsemi-circular notches or recesses 191, which accommodate the ends of thedrills, as will be apparent.

The rear end of the pan terminates in a vertical wall, which is bentover at its upper end as shown in Fig. 19, to form the bottom of thedischarge spout, the top of which is curved as shown. This spout isdesigned to discharge the muck upon an endless conveyer, and Ipreferably use an endless belt conveyer 196, which is mounted on rollers197, which are j ournaled in bearings .198, secured to parallel bars 198which are suitably supported from the bottom beams of the frame, andthese bars extend above the upper rim of the belt, and prevent'thematerial discharged thereon from rolling over the sides of the belt.

When the drilling engines are in operation against the breast of atunnel, the exhaust air flows from them to the chamber 195 in the bottomof the pan, and this air being under high pressure rushes to the lipportion of the bottom of the pan and then flows through the air passagesbetween the strips of the floor 194:, at a backward angle that will moveand force the muck that falls on the lip portion of the conveyerbackward over the said floor, and out of the discharge spout 193 at therear end of the conveyer onto the belt conveyer, by which it is conveyedto the rear end of the tunneling machine. As the drilling head movesfrom'one side of the tunnel to the other, the shoveling lip moves underany muck that accumulates on the fioor outside of the curtains, andgathers it up. This endless belt conveyer is operated from acounter-shaft 199, journaled in bearings 200, secured upon a beam 201,which is supported between the rear standards 5. This counter-shaft isdriven by a bevel gear 202, mounted on the rear end portion of the shaft53. The bevel gear 202 meshes with a bevel gear 203, that is secured tothe end of the counter-shaft 199. A sprocket wheel 204 is secured on theshaft, from which a sprocket chain 205 extends to a sprocket wheel 206,mounted on the axle of the rear end roller of the conveyer belt. Thisbelt discharges upon a belt 206 which is mounted on rollers 207 and 208.The roller 207 is supported in brackets attached to the rear end of theframe, and the roller 208 is supported in bearings mounted on a beam209, extending from the rear end of the frame. The belt is operated by asprocket chain 210, which is driven by a sprocket wheel 211 on thecounter shaft 199, and which passes around a sprocket wheel 212 on theshaft of the roller 208.

In Fig. 28, is illustrated a form of drill head 213, in which the drillsare arranged in radial order, and are extended from the floor linearound the head until the uppermost drill 214 is in line withorsubstantially in line with the axis of the head. With the drillsarranged thus, an arched tunnel is formed, as the head swings from sideto side, and by supplying the lower end of the head with drills 215,arranged in the order shown, a muck channel 216 may be formed in thebottom of the channel, as shown in Fig. 29, which figure also shows thewhole contour of the tunnel formed by the head 218. 1

An oil receiving reservoir 1 is secured upon one side of the drill head,and is connected at one end by a pipe 2 with the exhaust air chamber ofthe drill head. This reservoir is connected with a hollow ring 3*, fromwhich a plurality of oil tubes 4 extend to apertures 5 (Figs. 5 and 7 inthe side of the drill head, and these apertures register with annulargrooves 6 Fig. 31 in the piston hammer sleeve, and this groove 1sintersected by a longitudinal groove 7 which is intersected by avertical aperture 8 that opens against the hammer piston, and by thisarrangement of grooves and pipes oil from the reservoir 1 is forced bythe exhaust air within the piston hammer cylinder to lubricate the same.

Arms 9 are secured to the side of the drill head which carry rollers 10at their outer ends, which are adapted to bear against the breast of thetunnel, and prevent the machine from being fed against the breast of thetunnel faster than the drills can cut.

The sides of the main frame are provided with housing plates 11 whichprotect the operating mechanism and the operator as well.

The operation of my improved tunneling machine is as follows: Thereceiver is provided with a supply of compressed air through the pipe51, from an air compressing plant, which is located outside of thetunnel but which I do not illustrate. This air from the receiveroperates the engine 4-1, which runs the driving shaft 53*, and thedrilling head swinging and reversing mechanism. The compressed airdirect from the receiver operates the drilling engines, and the exhaustair from the drilling engines is used in the muck shoveling conveyer ofthe drilling head, while the endless belt conveyer is driven from themain driving shaft.

The frame is guided to cause the drilling head to drill a tunnel at anydesired grade, either straight or curved, by raising or lowering therear end of the frame, and by manipulating the side arms 37 to move themachine to either one side or the other of the center of the tunnel. Thedrilling head is manipulated to swing in the arc of a circle, from oneside of the tunnel to the other, and its movements can be reversed byhand, or it will reverse itself automatically. The drilling engines anddrill bit are preferably arranged to drill a slightly curved breastvertically as shown in Fig. 1, but can be arranged to drill a straightbreast tunnel if desired, and one having either a flat or an archedroof.

The swinging head allows the drill bits to strike the rock breast at thesides and at the angle of the floor and roof, with the breast, atsubstantially right angles to the line of greatest resistance the faceof the rock presents to the drilling ends of the drill bits, and as therock muck is drilled it falls on the air operated muck conveyer and iscon veyed by the exhaust air to the belt conveyer 196. by which it isconveyed and discharged to the rear of the frame, and as the drillinghead reciprocates across the breast of the tunnel, the drill bits strikeit with powerful blows, which are struck with great rapidity, and as thedrilling points of these drill bits are arranged to overlap the drillingarea of each other, they drill off the entire surface area of the breastof the tunnel, and as the head swings slowly around from one side to theopposite sides, the breast of the tunnel is rapidly drilled away, andthe operator feeds the frame forward by swinging the lever 31 to turnthe worm pinion 24: and its gear 23 to rotate the rear wheels to movethe frame forward as fast as the drill cuts away the rock.

The drilling head, when standing at substantially or fully at rightangles to the side walls of the tunnel, strikes square right angle blowsagainst the surface of the rock, thus insuring that the tunnel will bemaintained at the full width of the sides as well as at the angles ofthe roof and floor, with the breast, and should any part of the breastbe much harder than the rest, the operator can stop the drilling head inits regular swinging stroke and feed the drilling head back and forthover it by reversing the valve of the reversing mechanism with the handoperating lever 117 as long as desired.

My invention contemplates a centrally pivoted swinging oscillating andreciprocating multiple drilling engine and drill bit holding drillinghead, operatively arranged and supported on a suitable portable carriageadapted to be guided to permit said drilling head to drill tunnels ofany desired degree of inclination, vertical or horizontal curvature; andwhile I have illustrated and described the preferred construction andarrangement of my improved tunneling machine, I do not wish to belimited to the con struction and arrangement shown, as many changesmight be made without departing from the spirit of my invention.

Having described my invention, What I claim as new and desire to secureby Letters Patent, is:

1. In a tunneling machine, the combina tion of a frame provided withwheels at its front end, and with bearing boxes at its rear end, witheccentrics rotatably mounted in said boxes, an axle having the rearwheels mounted therein, said axle being-rotatably journaledin saideccentrics, semi-circular bands surrounding the wheels and provided withapertures; yoke levers which straddle said bands and are secured attheir ends to the eccentrics; removable pins for adjustably locking thelevers to the bands; and means including gearing for rotating said rearwheels to move said frame along a tunnel.

2. In a tunneling machine, the combination with a supporting frame,bearings on said frame, sleeves mounted in said bearings, a shafteccentrically mounted in said sleeves and supporting wheels on saidshafts; of semi-circular plates having apertures and secured to saidframe above said wheels, having a plurality of apertures; yoke levershaving apertures, said levers straddling said plates and wheels, andsecured at their ends to the adjacent sleeves, and removable pins whichare adapted to extend through apertures in the upper ends of the yokelevers, and through any one of the apertures in the said semi-circularplates, whereby the said sleeves may be turned and locked at any pointof adjustment.

3. In a tunneling machine, a supporting frame, a drilling head pivotallyattached to one end of said frame, means including gearing foroscillating said drilling head, in a semi-circular path from side toside of said frame, rock drilling engines and drill bits removablymounted in said drilling head, a supporting guideway for each drill bitprojecting from said head, muck confining curtains on.opposite sides ofsaid drill bits, means connected with said guide- Way and with said headfor supporting said curtains, and a muck conveyer securedto drill bitsand curtains, means for delivering a supply of compressed air into saidmuck pan for conveying the muck of said muck pan to the rear of saiddrilling head, and a suitable conveyer on said frame arranged to receivethe muck from said air operated muck shoveling pan and convey it to anddischarge it from the rear of said wheeled frame.

5. In a tunneling machine, the combination with a drill head, having acompressed air receiving chamber, an exhaust chamber, and parallel rowsof sockets which radiate from a common point, the sockets in each rowalternating with those in the other row, sleeves in said sockets andports connecting the receiving and exhaust chambers with said sleeves;drilling engines in said sleeves comprising piston hammers, valves foradmitting the actuating fluid to operate said. hammers, and strikingpins operated by said hammers, carrying drill bits, of means forlubricating said engines; comprising an oil receiving reservoirconnected at one end with the exhaust air chamber of the head, and atits opposite end with a hollow ring; and tubes connecting said ring withholes in the drill head, which register with oil passages in saidsleeve, connected with its interior.

6. In a tunneling machine, a supporting frame, a horizontally arrangedworm gear segment pivotally mounted on one end of said frame, a wormpinion in mesh with said worm gear, a drilling head pivoted to one endof said frame and secured to said worm gear to swing in a semi-circularpath across the end of said frame, a shaft extending through said wormpinion, oppositely arranged clutch faces on the opposite ends of saidworm pinion, inter-meshing clutches slidably mounted on said pinionshaft arranged to intermesh with the clutch faces of said pinion, meansincluding countershafts rotating in opposite directions for rotatingsaid slidable clutches in opposite directions, and means including avalve controlled cylinder and expansive fluid operating pistons formoving said sliding clutches in alternate order to engage the clutchesof said pinion to reverse the direction of movement of said pinion andgear and drilling head.

7. In a tunneling machine, the combination of the wheeled frame, a motorand a pair of oppositely rotating counter-shafts, driving connectionsbetween the motor and countershafts, a reversing mechanism comprising adriving shaft provided with reversely driven clutch mechanisms,connections to said countershafts for rotating said clutch mechanisms inopposite directions, a cylinder and fluid actuated valve-controlledpistons operatively mounted in said cylinder and operatively connectedto said reversely driven clutch mechanisms, and means for admittingfluid to the cylinder to operate said pistons.

8. In a tunneling machine, the combination of the frame, provided withoppositely rotating counter shafts, arranged to drive a shaft carrying aworm gear, said worm gear being also provided with oppositely arrangedclutch faces, sleeves oppositely rotatably and slidably mounted on saidshaft, having clutch toothed faces adapted to engage the clutch faces ofsaid worm gear, power transmission wheels slidably mounted on saidsleeves and arranged to be rotated in opposite directions by saidcounter-shafts, means for preventing axial rotation of said wheels uponsaid sleeves, and means including valve controlled fluid operatingpistons operatively connected to said oppositely rotating sleeves formoving them into clutch engaging contact with the clutch faces of saidpinion in alternate order.

9. In a tunneling machine, the combination of a frame, provided with arotatable shaft, a worm pinion secured on said shaft and provided withoppositely arranged clutch faces, rotatable clutch members slidablymounted on said shaft to register with said clutch faces,-means-including a compressed air operating motor mounted on said framefor rotating said clutches in opposite directions, a rock arm pivotallysupported intermediate of its ends, and adjacent to each slidableclutch, a pivotal connection between one end of each rock arm and theadjacent sliding clutch, a valve controlled cylinder adjacent to saidrock arm provided with a central partition, pistons, mounted in saidbore on each side of said partition, and provided with piston rodsextending from said cylinder in opposite directions, a pivotalconnection between the opposite ends of said rock arms and theiradjacent piston rods, a port connecting said cylinders at the adjacentopposite sides of said partition, a sliding pin in said partitionadapted to be engaged by said pistons in alternate order to move theinoperative piston into operative relation to said port, a valve cheston said cylinder provided with actuating fluid inlet and exhaust portsleading into the opposite ends of said cylinder, and into and from saidvalve chest, a slide valve in said valve chest arranged to control saidports, means for moving said valve to reciprocate said pistons toalternately move said power driven sliding clutch members into and outof coupling contact with the clutches of said worm-pinion shaft, a gearin mesh with and adapted to be rotated in reverse rotary direction bysaid worm pinion and said clutches, and a drilling head provided with aplurality of vertical rows of operative drilling engines pivotallymounted on said frame and secured to said worm gear and arranged to beoscillated in a semi-circular path by said reversing mechanism.

10. In a tunneling machine, the combination with a wheeled frameprovided with a driving shaft provided with a power transmitting pinion,having reverse clutch faces, opposing clutch members slidably mounted onsaid shaft to register with the oppositely arranged clutch faces of saidpinion, means for rotating said slidable clutch members in oppositerotative directions, a cylinder in operative relation to said shaft, apair of fluid controlled pistons in said cylinder, means including rockarms for connecting said pistons with said slidable clutches, a valvefor controlling said pistons to move said slidable clutch members intoand out of said pinion clutch faces, and means for moving said valve, apower wheel arranged to be driven by the power wheel of said drivingshaft, and an operative rock drilling head pivotally mounted on saidframe and secured to said power wheel and arranged to be oscillated in asemi-circular path by said power driven pinion and wheel.

11. In a tunneling machine, a wheeled frame provided with an oscillatingdrilling head and with a reversing mechanism, for driving and reversingsaid head, comprising a driving shaft mounted on said wheeled frame andprovided with a power transmitting wheel, having oppositely arrangedclutch faces, and having sliding and rotary clutch members mounted onsaid driving shaft in engaging relation to said wheel clutch faces, andmeans mounted on said wheeled frame for rotating said clutch members inopposite rotative directions, with a fluid actuating cylinder providedwith a pair of pistons, means including rock arms for connecting saidpistons and sliding clutch members together, and means includ ing amanually operated valve for reversing the direction of engaging anddisengaging movements of said sliding clutch members, relative to theclutch faces on said driving shaft, and a power receiving wheel inoperative driven relation to said driving shaft.

12. In a tunneling machine, the combina tion of a wheeled frame, adriving shaft rotatably journaled on said wheeled frame, and providedwith aworm pinion having reverse direction rotating clutch faces on itsends, oppositely rotating power operated sliding clutch members arrangedto register with said gear and shaft driving clutch faces, and meansincluding a cylinder and a pair of pistons and piston rods arranged tomove in the same direction in successive order in said cylinder, a valvefor controlling the operating fluid and means for operating it, andoperative connections between said pistons and said sliding clutchmembers to move one out of engagement with its adjacent pinion clutchface, and to successively move the opposite clutch member intoengagement with its adjacent pinion clutch face-whereby the direction ofrotation of said worm pinion is reversed in alternate order, a worm gearin mesh with said pinion, a drilling head provided with an operativegroup of drilling engines secured to said gear and pivotally mounted tosaid wheeled frame, and arranged to be oscillated ahead of said frame inoperative rock drilling relation to the breast of a tunnel.

13. In a tunneling machine, a wheeled frame provided with a rockdrilling head, arranged to be oscillated ahead of said frame, across thebreast of a tunnel, and provided with a reversing mechanism, consistingof a driving shaft provided with a worm pinion having reverse clutchfaces, reversely' rotating power-driven sliding sprocket wheels andclutch members mounted on said driving shaft, means including a motormounted on said frame for driving said sliding sprocket wheels andclutch members in opposite directions, a cylinder, a pair of pistons andpiston rods in said cylinder a valve and means for operating it tocontrol the movements of the pistons, and operative connections betweensaid piston rods and clutch-members.

14. In a tunneling machine, the combina tion of a wheel frame providedwith a driven shaft, oppositely rotating sprocket wheels and clutchmembers on said driven shaft, and means mounted 011 said frame fordriving said sprocket wheels and clutches in opposite directions on saidshaft, with a cylinder provided with two piston bores in axial alinementseparated by a partition positioned centrally between them, an air portextending from one cylinder past said partition, and entering eachcylinder at a short distance from said partition, a piston head in eachcylinder narrower than the space between said partition and the entranceto said port, a sliding pin in said partition arranged to be engaged byeach piston in alternate order and to move the other piston far enoughaway from said partition to receive air from said port between said portand said partition, piston rods projecting from said pistons through andbeyond said cylinder, grooved collars on said sliding clutch members,rock arms connected with said piston rods and with said grooved collars,a valve chest on said cylinder, air inlet and exhaust outlet aperturesleading into and out of said valve chest and from said valve chest intothe outer and opposite end portions of said cylinders, a slide valve insaid valve chest, and means for reversing said slide valve, whereby thepistons are reversed to rock the said arms in alternate order.

15. In a tunneling machine, a wheeled frame, a driving shaft journaledon said frame, provided with a worm pinion having oppositely arrangedclutch faces formed on its opposite ends; sleeves having clutch facesmounted on the shafts and adapted to engage the clutch faces of thepinion; sprocket wheels mounted on said clutch sleeves and feather keysconnecting said sleeves and sprocket wheels; means including a motor andshafting and sprocket wheels and chains for rotating the sprocket wheelsand clutches of said driving shaft in opposite directions, groovedcollars on said sleeves, rock arms pivotally supported intermediate oftheir ends and provided with yoke ends which straddle said collar,having lugs which project into said grooved collars, means including avalve controlled fluid actuating cylinder and a pair of pistonsreciprocally mounted therein, having piston rods pivotally connected tothe opposite ends of said rock arms, for reciprocally moving saidsliding clutch members in alternate order into and out of operativeengagement with the clutch faces of said worm, and a worm wheel in meshwith said worm pinion and arranged to be operated thereby, and adrilling head secured to said worm gear and pivotally mounted on one endof said wheeled frame and provided with a tunnel driving group ofdrilling engines and arranged to be oscillated across the breast of atunnel by said driving shaft and its worm pinion.

16. In a tunneling machine, the combination of a wheeled frame, adriving shaft journaled on said frame and provided with a worm gearpinion, oppositely pitched clutch faces at the ends of said pinion,sleeves each having a clutch face slidably mounted on said shaft, eachclutch face being arranged to face one of the clutch faces of saidpinion and adapted to engage it, a sprocket on each slidable clutchsleeve, means mounted on said frame for rotating said sprockets andclutch members in opposite directions, a fluid receiving cylinderadjacent to said driving shaft, provided with two independent pistonbores, operative actuating fluid ports in said cylinder for operatingsaid pistons in unison, a valve arranged to control said ports, a pairof piston heads and piston rods reciprocally mounted in said cylinderbores, means in-'- eluding rock arms for connecting said piston rods tosaid sleeve, a driven gear in mesh with the worm pinion ofsaid drivingshaft, a manually operating lever connected to said valve, and meansincluding engaging projections connected with said worm gear and valvelever for automatically moving said lever and valve, a drilling headpivotally mounted on said wheeled frame, and secured to and carried bysaid driven gear, a plurality of vertical rows of rock drilling engineso-peratively mounted in said drilling head to drill away the breast of atunnel, and means including an air receiver on said wheeled frame foroperating said drilling engines.

17. In a tunneling machine, the combination of the wheel frame, acounter-shaft journaled at the center of the top of said frame, abeveled gear on the end of said shaft, means including an engine on saidframe for rotating said shaft, a pair of countershafts journaled onopposite sides of the axial center of said shaft, provided with bevelgears arranged in mesh with the bevel gear of said shaft whereby saidcountershafts are rotated in opposite directions, sprocket wheelsmounted on each of said counter-shafts, a worm pinion provided withshaft ends journaled on said frame parallel with and adjacent to saidcountershafts, sleeves having clutch faces on said shaft, sprocketwheels slidably mounted on said clutch sleeves, sprocket chains mountedon the sprocket wheels of said counter-shaft and extending to theadjacent sprocket wheel of said pinion shaft, oppositely arranged clutchfaces on the opposite ends of said pinion, with which said clutchsleeves are adapted to engage in alternate order, means including anactuating fluid operating valve controlled cylinder and a pair ofpistons for alternately operating the clutch sleeves to engage theclutch faces of said pinion and reverse the direction of rotary movementof said pinion, a segmental worm gear in mesh with said pinion, adrilling head pivotally attached to the adjacent end conveyer arrangedon said head and frame.

18. In a tunneling machine, a supporting frame, a drilling headpivotally mounted on said frame; a worm gear connected to said head; aworm pinion in mesh with said worm gear, having clutch faces on itsopposite ends; slidable sleeves having clutch faces adapted to engagealternately with said clutch faces of the pinion; means for rotatingsaid sleeves in opposite directions; a fluid operated engine havingaxially alined twin cylinders, pistons, and piston rods; a leverconnecting each piston rod with a sleeve; a valve chest upon saidengine; a slide valve in said chest adapted to admit actuating fluid tosaid engine cylinders alternately; a rod extending from said valve; ahand lever pivotally connected with said rod and with a rock levermounted on said engine; a vertical bar extending down from said rocklever, and having a roller mounted on its lower end; a cam on said gearadapted to raise said roller and bar at the limit of movement of saidgear in one direction to move the slide valve, and a second cam on saidworm gear adapted to engage said roller to draw said bar down, andreverse the position of the slide valve, when the said worm gear reachesthe limit of its movement in the opposite direction.

19. A tunneling machine having an oscillating drill-head and means foroperating it, drilling engines and bits mounted in said head, a muckconfining housing secured to said head, and a conveyer secured to theunder side of said drill-head and to said housing.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE AHFOXVLER.

Witnesses:

G. SARGENT ELLIOTT, ADELLA M. FowLn.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

